In a wireless network, the connectivity and communication between devices is achieved using antennas that are coupled to receivers or transmitters, in order to radiate the desired signals to or from other elements of the network. In conventional radio communication systems, such as millimeter-wave radios, discrete components are usually assembled with low integration levels. These systems are often assembled using expensive and bulky waveguides and package-level or board-level microstrip or stripline structures to interconnect semiconductors and their required transmitter or receiver antennas. With recent progress in semiconductor technology and packaging engineering, the dimensions of these radio communication systems have become smaller.
With some state of the art technologies, multilayer integrated antenna structures can be fabricated using multilayered printed circuit boards (PCB) (organic-based) or using low temperature co-fired ceramic (LTCC) technology (ceramic-based). These multilayered organic or ceramic integrated antenna structures can be connected to semiconductor IC chips using standard C4 (controlled collapse chip connection) techniques. Integrated antenna structures that are made with organic or ceramic-based packaging techniques are generally suitable for application operating frequencies in the 60 GHz band while achieving suitable performance. However, for operating frequencies in the 94 GHz band and above, the use of organic or ceramic-based multilayer antenna structures becomes problematic due to, e.g., low PCB and LTCC manufacturing tolerances and resolutions. Moreover, the package materials used for PCB and LTCC technologies are too lossy for high frequency applications. Thus, it is desirable to design package structures with integrated antennas coupled to semiconductor IC chips (e.g., RFIC chips) that provide high performance operation for applications with operating frequencies in the 94 GHz band and higher.